On the Phelps-Koopmans Theorem

We examine whether the Phelps-Koopmans theorem is valid in models with nonconvex production technologies. We show by example that a nonstationary path that converges to a capital stock above the smallest golden rule may indeed be efficient. This finding has the important implication that "capital overaccumulation" need not always imply inefficiency. We provide general conditions on the production function under which all paths that have a limit in excess of the smallest golden rule must be efficient, which proves a version of the theorem in the nonconvex case. Finally, we show by example that a nonconvergent path with limiting capital stocks bounded above (and away from) the smallest golden rule can be efficient, even if the model admits a unique golden rule. Thus the Phelps-Koopmans theorem in its general form fails to be valid.

A Comprehensive Study Of Esterification Of Free Fatty Acid To Biodiesel In a Simulated Moving Bed System

Simulated Moving Bed (SMB) systems are used for separations that are difficult using traditional separation techniques. Due to the advantage of adsorption-based chromatographic separation, SMB has shown promising application in petrochemical and sugar industries, and of late, for chiral drug separations. In recent years, the concept of integration of reaction and in-situ separation in a single unit has achieved considerable attention. The simulated moving bed reactor (SMBR) couples both these unit operations bringing down the operation costs while improving the process performance, particularly for products that require mild operating conditions. However, its application has been limited due to complexity of the SMBR process. Hence, to successfully implement a reaction in SMB, a detailed understanding of the design and operating conditions of the SMBR corresponding to that particular reaction process is necessary. Biodiesel has emerged has a viable alternative to petroleum-based diesel as a renewable energy source in recent years. Biodiesel can be produced by esterification of free fatty acids (present in large amounts in waste oil) with alcohol. The reaction is equilibrium-limited, and hence, to achieve high purity, additional purification steps increases the production cost. Therefore, combining reaction and separation in SMBR to produce high purity biodiesel is quite promising in terms of bringing down the production cost. In this work, the reversible esterification reaction of oleic acid with methanol catalyzed by Amberlyst 15 resin to form methyl oleate (biodiesel) in SMBR has been investigated both theoretically and experimentally. First, the adsorption and kinetic constants were determined for the biodiesel synthesis reaction by performing experiments in a single column packed with Amberlyst 15, which acts as both adsorbent and catalyst. Thereafter, a rigorous model was used to describe the dynamic behaviour of multi-column SMBR followed by experimental verification of the mathematical model. Sensitivity analysis is done to determine robustness of the model. Finally, a few simple multi-objective optimization problems were solved that included both existing and design-stage SMBRs using non-dominated sorting genetic algorithm (NSGA). Pareto-optimal solutions were obtained in both cases, and moreover, it was found that the performance of the SMBR could be improved significantly under optimal operating conditions

Persistence Problem in Two-Dimensional Fluid Turbulence

We present a natural framework for studying the persistence problem in two-dimensional fluid turbulence by using the Okubo-Weiss parameter $\Lambda$ to distinguish between vortical and extensional regions. We then use a direct numerical simulation (DNS) of the two-dimensional, incompressible Navier--Stokes equation with Ekman friction to study probability distribution functions (PDFs) of the persistence times of vortical and extensional regions by employing both Eulerian and Lagrangian measurements. We find that, in the Eulerian case, the persistence-time PDFs have exponential tails; by contrast, this PDF for Lagrangian particles, in vortical regions, has a power-law tail with an exponent $\theta=2.9\pm0.2$.Comment: consistent with the published versio

Implications of an Economic Theory of Conflict: Hindu-Muslim Violence in India

We model intergroup conflict driven by economic changes within groups. We show that if group incomes are low, increasing group incomes raises violence against that group and lowers violence generated by it. We then apply the model to data on Hindu-Muslim violence in India. Our main result is that an increase in per capita Muslim expenditures generates a large and significant increase in future religious conflict. An increase in Hindu expenditures has a negative or no effect. These findings speak to the origins of Hindu-Muslim violence in post-Independence India

The effect of low dose glargine U 300 on uncontrolled type 2 diabetes mellitus. An observational study in Indian patients

Introduction. Insulin therapy plays an important role in the management of diabetes mellitus. The primary goal of insulin therapy is to achieve the best possible glycemic control without hypoglycemia. First-generation basal insulin (BI) analogues, such as insulin glargine 100 U/mL (Gla-100) and insulin detemir (IDet), provide more prolonged and stable activity than neutral protamine Hagedorn (NPH) insulin, with a lower risk of hypoglycemia. Insulin glargine 300 U/mL (glargine U 300) is a long acting basal insulin analogue approved for the treatment of diabetes mellitus. Insulin glargine 300 U/mL has a more stable and prolonged pharmacokinetic/pharmacodynamics profile than insulin glargine 100 U/mL, with a duration of glucose-lowering activity exceeding 24 h. Although the average daily insulin dose was higher, hypoglycemia episodes were lower in patients treated with Gla-300 compared with those treated with Gla-100. This is due to a more extended time action profile than Gla-100 resulting in a more stable and sustained glycemic control. The formulation of Gla-100 delivers the same amount of Insulin as Gla-300, in a third of the injection volume. It is essential to determine whether the clinical benefits of hypoglycemia reduction observed with insulin glargine in RCTs translate into a real-life clinical practice setting. Materials and methods. Fifty patients diagnosed with type 2 diabetes mellitus with uncontrolled plasma glucose levels (HbA1c of > 7.5) who were on oral hypoglycemic agents, premix insulin and basal bolus therapy were enrolled into the study and started on glargine U 300 at a dose of 0.2 IU/kg and analysed for glycemic and kidney function parameters. The patients were followed up at 3 and 6 months post treatment. Results. All glycemic control parameters decreased significantly with almost a 50% decline in both FBS and PBS from baseline to 6 months. The HbA1c decreased significantly from baseline to 3 months and 6 months post treatment by 18% and 29% respectively. All biochemical parameters were found to be statistically significant in both groups. Conclusions. In patients with uncontrolled type 2 diabetes, switching from either OHAs or insulin to Gla-300 improves glycemic control, with a low incidence of hypoglycemia. These results confirm the effectiveness and safety of Gla-300 in a real-world setting and show that Gla-300 is a suitable therapy option for patients with diabetes

Microwave Theory

Contains reports on three research projects

Relationship of Staff Engagement and Perception of Safety Scores with Patient Outcomes

Abstract Category: Research Purpose: To explore clinical nurses’ perception of engagement and patient safety and evaluation of correlation between engagement and perception of patient safety to patient outcomes. Methods: Exploratory component of clinical nurses’ perceptions of engagement and patient safety involved a nontraditional qualitative descriptive research design with focus group led by staff nurse unit-based practice council chairs and thematic analysis. Correlational component consisted of parametric statistical analysis of National Database of Nursing Quality Indicators (NDNQI) RN Satisfaction scores, Agency for Healthcare Research and Quality Hospital Survey of Patient Safety Culture scores (PSCS), and patient outcomes data from 2012, 2014, and 2016. Findings: Findings revealed statistically significant correlated relationships between NDNQI RN satisfaction (reflected in practice environment score (PES) & PSCS (r=0.756, p=0.004); PES & patient falls (r=0.577, p=0.049); and between handoff reports (element of PSCS) & patient falls (r=0.726, p=0.008). Focus group themes include: team building activities, being engaged with patient, teamwork, and being emotionally attached related to engagement; and staffing/assignment, patient care, and teamwork related to safety. Discussion: Evidence exists of a relationship between higher RN job satisfaction and/or a positive patient safety culture and patient outcomes; but limited studies exist showing a statistically significant relationship. Furthermore, limited studies have been conducted exploring perceptions of nurses and whether there is a relationship between perceptions and actual outcomes. The results of this study show there is statistically significant correlation between RN satisfaction and falls (higher RN satisfaction, lower number of falls); and between handoffs (an element of safety perception) and falls (higher perception of handoffs as important, lower number of falls). The common themes for engagement that transcended across groups were teamwork and being emotionally attached and caring and for safety common theme was staffing, acuity and assignment. Implications for Practice: By keeping staff engaged and patient safety-centered and focusing on what nurses themselves perceive as elements of staff engagement and patient safety, leaders can potentially positively affect patient outcomes. Having nurses themselves work collaboratively to identify how they affect patient outcomes through a deeper understanding, translates to a stronger safety culture and enhanced patient care